It is known to shield the microphone system of hearing aids against electromagnetic interference and to configure them with respect to acoustic resonance chambers. It is further known about hearing aids processing digital audio signals to use an analog/digital converter directly subsequent to the microphone system.
German patent 195 457 60 proposes configuring the analog/digital converter with the microphone system into one unit in the hearing aid and to shield both jointly against electromagnetic interference.
This design incurs a number of drawbacks:                Each further development of analog/digital converters on one hand and of the microphone system on the other hand requires a new design of the combined, integral unit,        The advantage of one and the same analog/digital converter being combinable with various microphone systems, or that one and the same microphone system might be combined with different AD converters, is precluded as regards lowering the manufacturing costs of the individual components,        When designing the microphone system, the analog/digital converter, which is integral therewith, must also be considered in the light of the acoustic resonance chambers directly coupled to the microphone.        